Abstract
Hypertrophic cardiomyopathy (HCM) is a genetic condition characterised by the development of left ventricular hypertrophy (LVH) in the absence of hypertension and valve disease. HCM is common, occurring in approximately 1:500 of the general population, though most patients are asymptomatic. The condition has been found to be a frequent cause of sudden death in young adults and sportsmen and women. There are a number of risk factors for sudden death in HCM, with severe LVH being one of the main risk factors for disease progression in HCM.
Cardiotrophin-1 (CT1) is part of the IL-6 cytokine family and has been shown to induce cardiomyocyte growth and survival, thus promoting structural changes in the myocardium. CT1 is secreted by the coronary sinus into the peripheral circulation. Concentrations of CT1 have been found to be elevated and correlated with the severity of heart disease in patients with left ventricular failure typical of cardiac diseases such as hypertensive heart disease, aortic stenosis, coronary aortic disease and dilated cardiomyopathy. In this study the authors hypothesized that CT1 may be involved in the pathogenesis of LVH in HCM.
Consecutive patients (78 male, 46 female) were evaluated according to a protocol which included measurement of plasma CT1, exercise testing and an echocardiogram enabling the measurement of left ventricular wall thickness. The patients with HCM were compared to a control population of 29 subjects. CT1 concentrations were found to be significantly (P < 0.001) increased in patients with HCM (137 ± 72 pmol/L) compared to controls (18 ± 12 pmol/L). All HCM patients exhibited concentrations of CT1 above the upper limit of normal of the control population. CT1 concentrations were highest in patients with the most severe LVH (maximal LV wall thickness ≥30 mm).
A marker that could be used to diagnose the severity of LVH in HCM patients would allow the assessment of these patients to identify those most likely to suffer from sudden death. Further assessment of CT1 in a larger prospective study is required to assess if it is of value for diagnosis of the most severe forms of LVH in HCM patients or if it can add prognostic information in these patients.